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Diffstat (limited to 'block/qcow2.c')
-rw-r--r--block/qcow2.c111
1 files changed, 100 insertions, 11 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index 0f1be2e384..f9e045ff2b 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -442,6 +442,22 @@ static QemuOptsList qcow2_runtime_opts = {
.type = QEMU_OPT_BOOL,
.help = "Check for unintended writes into an inactive L2 table",
},
+ {
+ .name = QCOW2_OPT_CACHE_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Maximum combined metadata (L2 tables and refcount blocks) "
+ "cache size",
+ },
+ {
+ .name = QCOW2_OPT_L2_CACHE_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Maximum L2 table cache size",
+ },
+ {
+ .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Maximum refcount block cache size",
+ },
{ /* end of list */ }
},
};
@@ -457,6 +473,61 @@ static const char *overlap_bool_option_names[QCOW2_OL_MAX_BITNR] = {
[QCOW2_OL_INACTIVE_L2_BITNR] = QCOW2_OPT_OVERLAP_INACTIVE_L2,
};
+static void read_cache_sizes(QemuOpts *opts, uint64_t *l2_cache_size,
+ uint64_t *refcount_cache_size, Error **errp)
+{
+ uint64_t combined_cache_size;
+ bool l2_cache_size_set, refcount_cache_size_set, combined_cache_size_set;
+
+ combined_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_CACHE_SIZE);
+ l2_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_L2_CACHE_SIZE);
+ refcount_cache_size_set = qemu_opt_get(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE);
+
+ combined_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_CACHE_SIZE, 0);
+ *l2_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_L2_CACHE_SIZE, 0);
+ *refcount_cache_size = qemu_opt_get_size(opts,
+ QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0);
+
+ if (combined_cache_size_set) {
+ if (l2_cache_size_set && refcount_cache_size_set) {
+ error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE
+ " and " QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not be set "
+ "the same time");
+ return;
+ } else if (*l2_cache_size > combined_cache_size) {
+ error_setg(errp, QCOW2_OPT_L2_CACHE_SIZE " may not exceed "
+ QCOW2_OPT_CACHE_SIZE);
+ return;
+ } else if (*refcount_cache_size > combined_cache_size) {
+ error_setg(errp, QCOW2_OPT_REFCOUNT_CACHE_SIZE " may not exceed "
+ QCOW2_OPT_CACHE_SIZE);
+ return;
+ }
+
+ if (l2_cache_size_set) {
+ *refcount_cache_size = combined_cache_size - *l2_cache_size;
+ } else if (refcount_cache_size_set) {
+ *l2_cache_size = combined_cache_size - *refcount_cache_size;
+ } else {
+ *refcount_cache_size = combined_cache_size
+ / (DEFAULT_L2_REFCOUNT_SIZE_RATIO + 1);
+ *l2_cache_size = combined_cache_size - *refcount_cache_size;
+ }
+ } else {
+ if (!l2_cache_size_set && !refcount_cache_size_set) {
+ *l2_cache_size = DEFAULT_L2_CACHE_BYTE_SIZE;
+ *refcount_cache_size = *l2_cache_size
+ / DEFAULT_L2_REFCOUNT_SIZE_RATIO;
+ } else if (!l2_cache_size_set) {
+ *l2_cache_size = *refcount_cache_size
+ * DEFAULT_L2_REFCOUNT_SIZE_RATIO;
+ } else if (!refcount_cache_size_set) {
+ *refcount_cache_size = *l2_cache_size
+ / DEFAULT_L2_REFCOUNT_SIZE_RATIO;
+ }
+ }
+}
+
static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
@@ -707,17 +778,43 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
}
}
- /* alloc L2 table/refcount block cache */
- l2_cache_size = DEFAULT_L2_CACHE_BYTE_SIZE / s->cluster_size;
+ /* get L2 table/refcount block cache size from command line options */
+ opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort);
+ qemu_opts_absorb_qdict(opts, options, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ read_cache_sizes(opts, &l2_cache_size, &refcount_cache_size, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ ret = -EINVAL;
+ goto fail;
+ }
+
+ l2_cache_size /= s->cluster_size;
if (l2_cache_size < MIN_L2_CACHE_SIZE) {
l2_cache_size = MIN_L2_CACHE_SIZE;
}
+ if (l2_cache_size > INT_MAX) {
+ error_setg(errp, "L2 cache size too big");
+ ret = -EINVAL;
+ goto fail;
+ }
- refcount_cache_size = l2_cache_size / DEFAULT_L2_REFCOUNT_SIZE_RATIO;
+ refcount_cache_size /= s->cluster_size;
if (refcount_cache_size < MIN_REFCOUNT_CACHE_SIZE) {
refcount_cache_size = MIN_REFCOUNT_CACHE_SIZE;
}
+ if (refcount_cache_size > INT_MAX) {
+ error_setg(errp, "Refcount cache size too big");
+ ret = -EINVAL;
+ goto fail;
+ }
+ /* alloc L2 table/refcount block cache */
s->l2_table_cache = qcow2_cache_create(bs, l2_cache_size);
s->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size);
if (s->l2_table_cache == NULL || s->refcount_block_cache == NULL) {
@@ -809,14 +906,6 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
}
/* Enable lazy_refcounts according to image and command line options */
- opts = qemu_opts_create(&qcow2_runtime_opts, NULL, 0, &error_abort);
- qemu_opts_absorb_qdict(opts, options, &local_err);
- if (local_err) {
- error_propagate(errp, local_err);
- ret = -EINVAL;
- goto fail;
- }
-
s->use_lazy_refcounts = qemu_opt_get_bool(opts, QCOW2_OPT_LAZY_REFCOUNTS,
(s->compatible_features & QCOW2_COMPAT_LAZY_REFCOUNTS));